Inorganic Contaminants:
* Dissolved Salts: RO membranes are excellent at removing dissolved salts like calcium, magnesium, sodium, potassium, chloride, sulfate, and bicarbonate. This makes RO effective for treating hard water and removing minerals that can contribute to scale build-up in pipes and appliances.
* Heavy Metals: Lead, mercury, arsenic, cadmium, and other heavy metals are effectively rejected by RO membranes, making it a crucial technology for removing these potentially toxic substances.
* Fluoride: While RO doesn't fully remove fluoride, it can significantly reduce its concentration, which is important for those concerned about fluoride levels in their water.
Organic Contaminants:
* Pesticides and Herbicides: RO membranes can remove a wide range of pesticides and herbicides from water, protecting human health.
* Pharmaceuticals: Many pharmaceuticals can be found in wastewater and even treated drinking water. RO is effective at reducing the presence of pharmaceuticals.
* Volatile Organic Compounds (VOCs): RO can remove a variety of VOCs, including those found in solvents, cleaning products, and industrial waste.
* Bacteria and Viruses: While RO membranes are not designed to kill microorganisms, they can effectively remove them due to their small size and inability to pass through the membrane.
Other Contaminants:
* Turbidity: RO effectively removes suspended particles, making it suitable for treating water with high turbidity levels.
* Color and Odor: RO can improve water clarity by removing dissolved organic matter that contributes to color and odor.
What RO Does NOT Remove:
* Dissolved Gases: Gases like oxygen, nitrogen, and carbon dioxide can pass through RO membranes.
* Viruses and Bacteria (Directly): RO membranes filter them out, but don't directly kill them.
* Very Small Molecules: Some very small molecules, like certain dissolved minerals, may pass through the RO membrane.
Factors Influencing Rejection:
* Membrane Type: Different RO membranes have varying rejection rates for different contaminants.
* Operating Pressure: Higher pressure generally leads to higher rejection rates.
* Feed Water Quality: High levels of certain contaminants can impact membrane performance.
Important Note: While RO is highly effective, it's crucial to remember that it's not a perfect solution. For the best results, it's often combined with other water treatment technologies like pre-filtration and post-treatment to address specific contaminants and improve overall water quality.
